The invention is directed to a method for the transmission of information in a universal transmission network in which mobile radiotelephone-specific and fixed network-specific functions are implemented.
The article "Mobilkommunikation auf Expansionskurs", in telcom report 18 (1995), No. 2, pages 52 through 55, discloses universal transmission networks (UMTS Universal Mobile Telecommunications System, FPLMTS Future Public Land Mobile Telecommunications System) in which different networks and network services are combined for person-related mobile telecommunication. A universal access to a transmission network in which mobile radiotelephone network related and fixed network related functions are implemented for voice, data and image communication thereby arises for the network subscribers, whether mobile radiotelephone subscribers or fixed network subscribers.
As known, the radiotelephone station of a network subscriber can transmit the same information on a plurality of redundant transmission paths that are set up parallel via a radio transmission interface from the network to the radiotelephone subscriber station or from the radiotelephone subscriber station to the transmission network (macro diversity) in order to achieve an optimally good transmission quality. This means that the signaling and/or useful information that are usually inserted into one or more transmission frames are received by a plurality of radio equipment, for example base transmission/reception stations of the transmission network. The information transmission via parallel redundant transmission paths is applied, for example, given a radio transmission interface that uses the CDMA access method (Code Division Multiple Access) according to U.S. Pat. No. 5,101,501. The redundant transmission paths can be dynamically set up and cleared down while the radiotelephone subscriber station changes its location. An operation in this transmission mode (macro diversity) is also possible over a longer time span given a stationary radiotelephone subscriber station.
In an ATM network with a utilization of a radio interface for the transmission of information from or, respectively, to a mobile station, EP-A-0 679 042 discloses that an improved transmission quality be obtained by a setup of redundant paths by the mobile station. The higher transmission capacity thereby required for the transmission of ATM cells in the access network between base stations with which the mobile station is in radio communication and a mobile network interface unit is reduced in that sub-networks are formed in the access network and redundant paths are combined or, respectively, divided in their interfaces (sub-network interfaces).
The information that are sent out by the radiotelephone subscriber station in the transmission frames on various transmission paths can be merged in the transmission network at combination points at which respectively two transmission paths are combined into a single transmission path in the one transmission direction (uplink) and the single transmission path is divided into two transmission paths in the other transmission direction (downlink). The plurality and distribution of the combination points onto network elements of the transmission network changes dynamically with the addition or, respectively, removal of redundant transmission paths that can be additionally set up or, respectively, in turn cleared down by the radiotelephone subscriber station.
For a best possible utilization of the network elements of the universal transmission network, it is necessary to determine a transition point at which mobile radiotelephone-specifically encoded information must be converted into fixed network-specifically encoded information. Since the transition point terminates all mobile radiotelephone-specific functions, a conversion can only ensue following all combination points given the presence of a plurality of redundant transmission paths in the transmission network. Changes in the plurality and distribution of the combination points and, thus, in the determination of the transition point in the transmission network derive due to the dynamic addition and removal of redundant transmission paths.